1. Field of the Invention
Aspects of the present invention relate to an image generation apparatus and method, and more particularly, to an image generation apparatus and method in which, by adjusting exposure amounts and resolutions thereof, a plurality of images are generated, and by synthesizing the plurality of the generated images, an image having a high dynamic range is generated.
2. Description of the Related Art
In general, when an apparatus capable of taking an image, such as a digital camera and/or a camcorder, takes a picture image of a subject against the light, in order to improve the sensitivity of the picture image, various images having different exposure amounts are generated, synthesized, and then provided to a user. For example, when an image of the subject is taken against the light, and if the exposure amount thereof is small, the contrast of the image becomes high due to a short exposure time. Accordingly, edges in the image become clear. On the other hand, if the exposure amount thereof is large, colors of the image become clear due to a long exposure time. Accordingly, by synthesizing the image with the large exposure amount and the image with the small exposure amount, a high-sensitivity (or quality) image is generated.
FIG. 1 is a diagram illustrating a related art process to generate an image. A device (not shown) capable of taking an image generates an image 11 with a small exposure amount, and an image 12 with a relatively large exposure amount than that of the image 11, and by synthesizing the generated images 11 and 12, a high-sensitivity (or quality) image 13 is generated.
Thus, in order to generate images having different exposure amounts, an image with a small exposure amount and an image with a large exposure amount are generated through different exposure times, respectively, and then synthesized. However, when generating the image with the large exposure amount, a user is inconvenienced by the required long exposure time because the user has to maintain a certain position for a predetermined time while the image is taken with a digital camera. Also, if the position of the subject changes while the user is maintaining the certain position, the image with the large exposure amount and the image with the small exposure amount become different and makes it difficult to generate a normal image. Furthermore, since the user keeps the certain position for the predetermined time, trembling of the user's hands occurs, causing blurring of the generated image.
In order to lessen the inconvenience to the user, several remedial methods call for changing the structure of an image pickup device, such as modifying the arrangement of color filters or differentiating the sensitivities of filters. However, these methods require additional processing operations by the image pickup device, such as demosaicing of the color filters, and a white balancing method.
An example of such changes is shown in U.S. Patent Publication No. 2006-0066750, which discloses an image sensor having a pixel array with odd rows of the pixel array made to have a short exposure time and even rows made to have a long exposure time. By adding the outputs of each pair of pixels from the odd rows and the even rows, a wide dynamic range of an image is enabled. However, the above method still requires a long exposure time and still does not provide a method of preventing blurring of an image due to trembling of hands.